The present invention relates generally to a retrofit door latch attachment for a push-button door latch which assists children and handicapped persons in unlatching the door.
Screen doors and combination screen and storm doors are commonly installed outside the main doors of homes, and hence swing outwards when opened. The door latches on the outside of such screen and combination doors are typically comprised of a hand pull or grip for fingers and, above the grip, a push-button latch actuator operated by the thumb. When operated, these door latches require first a pushing force from the thumb to engage the actuator and unlatch the door, and then a second pulling force from the fingers on the hand grip to pull the door outwardly and thereby pivoting away from the main door.
It has been found that such latches are often too difficult for children and handicapped persons to operate. This difficulty arises due to the fact that they require the use of both fingers and thumb and that a combination of pushing and pulling forces are needed. These latches are also mounted relatively high on the door adding to the difficulty experienced by children and handicapped persons in wheelchairs.
A number of devices are known to address this problem. For example, in U.S. Pat. No. 3,317,231 to Lindquist et al., an extension door handle is disclosed. Although this device does not interfere with the manual actuation of the door latch in the conventional manner, it does require that the user""s hand twist the handle and exert a force laterally of the door in a direction not wholly aiding the opening of the door. Furthermore, this device is comprised of a number of parts, including a rod, a pair of brackets, and numerous screws, washers and cotter pins, all adding to its cost of manufacturing. Another disadvantage is that the handle is located at one level which, although lower and easy to reach for children, may not be at the proper level for disabled persons or older children.
U.S. Pat. No. 4,006,927 to Recupero discloses a door handle attachment where a bracket is mounted to the hand grip and projects outwardly therefrom. A lever is pivotally mounted to the bracket with the handle end extending down below the hand grip. When the lever handle is pulled away from the door it engages the actuator, unlatching the door, and then pulls the door open. One major disadvantage of this device is that it interferes significantly with the manual actuation of the door latch in the conventional manner. The projecting bracket itself, the thickness of the lever and the spacing of the lever a substantial distance from the hand grip, all discourage the normal grabbing of the hand grip with the fingers and actuating the door latch with the thumb in the conventional manner. Thus a device designed to aid children now impedes the relatively taller adults who must then reach down and pull the lever handle which extends downwardly from the bracket.
Ideally a retrofit door latch attachment for a screen door or combination door would be simple in design, inexpensive to manufacture, interfere only minimally with the manual actuation of the door latch in the conventional manner and have a handle which can be gripped across a range of levels.
The retrofit door latch attachment of the present invention is a first class lever mounted at a pivot and lying tangentially, and in close proximity to, the hand grip of a push-button door latch. The pivot is formed by the interaction of the attachment with a convex surface of the door latch""s grip, usually formed as part of the grip. In one embodiment of the invention the lever is mounted to the convex hand grip by means of a countersunk fastener placed through holes formed through both the lever and grip. Other means of mounting the lever to the grip include some form of string flexible wrap such as electrical tape or a Velcro strap.
In other embodiments, include those incorporating a recess or a cup at the upper end of the lever which cups the latch actuator for limiting the amount of side-to-side movement of the lever during operation. Furthermore, the addition of a flexible boot to the upper end of the lever which envelopes the top of the push-button latch assists in limiting the access of inclement, moisture-bearing weather such as snow and ice into the push-button actuator.